Credit

Caption

Water on Mars. Computer artwork looking west over the flooded craters of the Aram Chaos region at sunset on Mars 3.5 billion years ago. This region lies to the east of the Valles Marineris (Mariner Valley). Mars is now a desert world, but erosion features seen on Mars today suggest that water once flowed there. The water was lost due to the thin Martian atmosphere and weak gravity. The topography of this artwork was drawn with Terragen software, using data from the laser altimeter on the Mars Global Surveyor probe.